Roller guide construction for chair jacks and the like



n a r Oct. 17, 1961 J MAURER T L 3,004,802

Filed Oct. 23, 1959 JNVENTORS Jbhndjfawrera BY Liar/muse6J.7aa ylor"" ATTORNEYS J. A. MAURER ET AL 3,004,802

ROLLER GUIDE CONSTRUCTION FOR CHAIR JACKS AND THE LIKE Oct. 17, 1961 2 Sheets-Sheet 2 Filed Oct. 23, 1959 INVEN 10125 John 4 Maren BY Clarence (,LT zofi 9/2044? (W 904d? ATTORNEYS United States Patent Office Ohio Filed Oct. 23, 1959, Ser. No. 848,243 14 Claims. (Cl. 308-6) Our invention relates to improvements in roller guides for chair jacks and the like, and more specifically to a roller guide construction for preferably guiding the jack sections of vertically movable chairs, such as dental chairs and the like. Even more specifically, our invention relates to a new and improved construction of adjustable roller guide which may be used advantageously for guiding the jack sections of vertically adjustable chairs and the like.

Most prior constructions of roller guides used for guiding the jack sections of vertically adjustable chairs, such as dental chairs, have included spaced rollers, usually vertically spaced sets of horizontally spaced rollers. Furthermore, these roller guides have been permanently set within the particular jack assembly, that is, the rollers have been rotatable about a permanently fixed axis formed on a roller shoe, which roller shoe is mounted in a preselected and permanently set position with respect to the particular jack sections being guided.

Thus, in the use of these prior roller guide constructions, it' has been necessary to maintain extremely close tolerances in the manufacture of the roller guides and jack assemblies in order that the jack sections will be properly guided during their vertical movement in raising and lowering the particular chair.

Furthermore, after a period of use of the particuiar jack assembly which will cause some wear, not only in the roller guide assembly, but also upon the surfaces of the jack section against which the roller guide assembly abuts, it is necessary to completely remove the original roller guide assembly and replace the same with a new assembly and possibly one which is slightly larger in size to accommodate the wear which has taken place on the jack section.

It is, therefore, not only necessary in use of these prior roller guide constructions to maintain extremely close tolerances in the manufacture of the jack assembly which results in high production costs, but also high maintenance costs are involved for the removal of worn parts and the special fabricating of new parts to fit the particular circumstances of wear encountered.

Various attempts have been made to eliminate this problem of high original production costs and high maintenance costs caused bythe particular form of roller guide construction previously used by providing some means in the mounting of the longitudinal guide construction whereby adjustments can be made from time to time to compensate for wear. None of these attempts, however, have been completely successful and, to our knowledge, a satisfactory adjustable roller guide construction has not been provided prior to the present invention.

For instance, one prior construction of roller guide devised in an attempt to provide an adjustable roller guide construction has used sets of rollers permanently mounted rotatable around fixed axes on a roller guide shoe, with the shoe being mounted against a particular vertical surface within the jack assembly and adjustable toward and away from this surface for moving the rollers inwardly and outwardly toward and away from the jack section being guided. This adjustment has been provided by the use of several adjusting screws bearing against the mounting surface of the roller guide shoe to force the shoe into various positions with respect to its mounting surface.

The principal difliculty with this form of adjustable roller guide construction is that it is an extremely delicate adjusting problem to adjust one or a series of adjusting screws so that each roller of a given set of rollers is moved exactly the same amount and in exactly the proper direction, and this delicate adjustment is virtually impossible where a series of sets of rollers and a series of adjustment screws are provided which must act against the single shoe of the roller guide construction mounting the series of sets of rollers.

Further, if the resulting adjustment of the rollers of the roller guide construction is different between the various rollers, it will not only cause uneven wear on the rollers and the jack section being guided, but also can cause the jack section to bind during its necessary vertical movement. This is particularly true after a number of such adjustments have been attempted and has resulted in serious maintenance problems.

It is, therefore, a general object of the present invention to provide a roller guide construction for chair jacks and the like which solves the problems and eliminates the difficulties of the foregoing prior constructions.

It is a primary object of the present invention to provide a roller guide construction for chair jacks and the like in which various roller means are provided, all of which are simultaneously adjustable by a single adjustment means, thereby providing easy and exact adjustment of the roller means with respect to a jack section being guided thereby.

It is a further object of the present invention to provide a roller guide construction for chair jacks and the like in which a series of spaced sets of roller means may be provided, yet all of the sets of roller means and each roller means in each set may be simultaneously adjusted by a single adjusting means.

It is still a further object of the present invention to provide a roller guide construction for chair jacks and the like in which spaced sets of roller means may be provided simultaneously adjustable through a unique cam means connection and a single adjusting screw.

It is another object of the present invention to provide a roller guide construction which may be used in combination with jacks for chairs and the like, which jacks may include a series of jack sections, one telescoped within another, and each jack section is guided for vertical movement with respect to the jack section Within which it is telescoped by at least one of the unique roller guides of the present invention.

Finally, it is an object of the present invention to provide a roller guide construction for chair jacks and the like which satisfies all of the above objects in a unique and efficient manner and at a minimum of cost.

These and other objects are accomplished by the parts, constructions, arrangements, combinations and subcombinations comprising the present invention, the nature of which is set forth in the following general statement, a preferred embodiment of whichillustrative of the best mode in which applicants have contemplated applying the principles-is set forth in the following description and illustrated in the accompanying drawings, and which is particularly and distinctly pointed out and set forth in the appended claims forming a part hereof.

In general terms, the roller guide construction for chair jacks and the like comprising the present invention may be stated as including spaced roller means rotatably and adjustably mounted on a mounting shoe, for movement toward and away from the mounting shoe, and adjustment means for simultaneously moving all of the roller means toward and away from said mounting shoe. Furthermore, this roller guide construction may Patented Oct. 17, 196i be used in combination with a multiple-section jack, with said sections being telescoped and vertically reciprocal, and having at least one of the foregoing adjustable roller guides reciprocally mounting each of the vertically recipro-' cal jack sections.

More specifically, the roller guide construction may include a roller guide shoe which may be mounted stationary on a generally longitudinal or vertical mounting surface, with the roller guide shoe having side mounting bosses to which are attached hinge blocks rotatably mounting rollers.

Laterally or horizontally spaced sets of longitudinally or vertically spaced rollers may be provided, with each roller preferably being provided with its individual hinge block and with each hinge block having a longitudinal or vertical angled cam surface.

- Further, each set of rollers and hinge blocks may be provided with a cam block longitudinally or vertically slidably mounted on the roller guide shoe and having laterally or horizontally spaced angled cam surfaces slidably abutting the hinge block angled cam surfaces of the particular set of rollers.

Finally, a single adjustment screw may be provided journalled longitudinally or vertically through the roller guidev shoe and operably connected with each of the cam blocks for simultaneously moving the cam blocks to simultaneously move the hinge blocks and their respective rollers, through the slidable abutment of the cam block angled cam surfaces and hinge block angled cam surfaces.

By way of example, an embodiment of the roller guide construction for chair jacks and the like comprising the present invention is shown in the accompanying drawings forming a part hereof, wherein like numerals indicate similar parts throughout the several views, and in which:

FIG. 1 is a side elevation of a representative dental chair using a jack within which the roller guide construction of the present invention may he used;

FIG. 2, an enlarged fragmentary top plan view of the jack which may be used in the chair of FIG. 1;

FIG. 3, a fragmentary side vertical section, part in elevation, of the jack of FIG. 2;

FIG. 4, a front elevation of one of the permanently set or fixed axes roller guide assemblies removed from the jack shown in FIGS. 2 and 3;

FIG. 5, a top plan view of the permanently set or fixed axes roller guide assembly of FIG. 4;

FIG. 6, a front elevation, with parts broken away and in section, of one of the adjustableroller guide assemblies of the present invention removed from the jack shown in FIGS. 2 and 3, and in a particular adjusted position;

FIG. 7, a top plan view of the adjustable roller guide assembly of FIG. 6; and,

FIG. 8, a front elevation of the adjustable roller guide assembly of FIG. 6, but in a different adjusted position.

The roller guide construction for chair jacks and the like is illustrated in the drawings mounted in a particular jack, usable as the main jack of a dental chair, with this main jack being used for selectively moving the chair to various desired vertical positions. It should be understood, however, that the roller guide construction of the present invention may be used advantageously in various forms of jacks or where various reciprocal members are formed, and all such applications of the present invention are contemplated within the principles thereof.

A representative dental chair construction is generally indicatedat 10 in FIG. 1 and includes a chair assembly 11 and jack assembly 12. The purpose of the jack assembly 12 is, of course, for reciprocally vertically moving the chair assembly '11 to various heights with respect to a floor mount-ingsurface, which vertical reciprocation is accomplished in the usual manner by the manipulation of the various foot control pedals 13 of the jack assembly 12, with the jack assembly movement being controlled by hydraulic fluid pressure.

A fragmentary top plan view of the jack assembly 12 is shownin FIG. 2 and -a side vertical section thereof in FIG. 3. Jack assembly 12 includes the outer jack housing 14 having the cover ring v15, the intermediate jack section 16 having the cover ring 17 and the inner jack section 18.

In the particular embodiment shown in the drawings, an outer adjustable roller guide assembly 19 and an outer stationary roller guide assembly 20 telescopically and reciprocally mount the intermediate jack sect-ion 16 within the outer jack housing 14. Further, an inner adjustable roller guide assembly 21 and an inner stationary roller guide assembly 22 telescopically and reciprocally mount the inner jack section 18 within the intermediate jack section 16.

A fluid cylinder assembly 23 is mounted telescoped within and at least initially reciprocal with respect to the inner jack section 18, with the fluid piston assembly 24 being telescoped within the fluid cylinder assembly 23 and being mounted extending vertically within and stationary with respect to the outer jack housing 14. A fluid supply channel 25 is provided Within the fluid piston assembly 224 for supplying fluid to vertically reciprocate the fluid cylinder assembly 23, as will be hereinafter described in greater detail.

The particular configuration, construction and control of the jack assembly 12 may vary considerably, depending on the particular use involved and may be of many usual forms. In the particular embodiment shown, how ever, the outer jack housing 14 is provided with a circular generally vertical opening 26 forming the inner arcuate wall surface 27.

The outer stationary roller guide assembly 20 is mounted on wall surface 27 of the outer jack housing 14 at the top portion of the opening 26 and preferably directly underlying the cover ring 15 in any usual manner, with the stationary roller guide assembly 29 having the shoe 28 and the rollers 29. g

I Shoe 28 has the outer arcuate and generally vertically extending surfaces 30 which abut the wall surface 27 of the outer jack housing 14 and the inner generally V- shaped and vertically extending surface 31 opening inwardly toward the intermediate jack section 16.

Vertically spaced sets of the rollers 29 are mounted at the inner surface 3 1 of shoe 28, with the rollers 29 of each set being generally horizontally spaced. As shown in FIGS. 4 and 5, each roller 29 is mounted within a vertically extending groove 32 rotatable on a generally horizontally extending shaft 33, with the shaft being retained properly positioned by the set screw 34.

Thus, the rollers 29 are rotatable with respect to the shoe 28 and have outer cylindrical surfaces 35 extending a predetermined distance inwardly from the shoe inner surface 31 and generally parallel to this inner surface.

Due to the V-shape configuration of the shoe inner surface 31, the rollers 29 of each set are, therefore, somewhat angularly opposed and define a generally V-shaped roller plane.

The outer generally vertical surface 36 of the intermediate jack section 16 is provided with the generally outwardly V-shaped boss 37 forming the horizontally angled and vertically extending guide surfaces 38. The intermediate jack section 16 is telescoped Within the outer jack housing 14, with the guide surfaces 38 abutting the inwardly extending cylindrical surfaces 35 of rollers 29 on the outer stationary roller guide assembly 20, so that the intermediate jack section 16 will be guided during vertical reciprocal movement by the rollers 29, which rollers are, of course, mounted rotatable on fixed axes -The inner stationary roller guide assembly 22 is, for all practical purposes, identical in construction to the outer stationary roller guide assembly 20, having the shoe 39 mounted stationary with respect to the intermediate jack section 16 at the inner generally cylindical and vertically extending opening 40 and against the inner Wall surface 41 of intermediate jack section 16.

Further, the rollers 42 are mounted in vertically spaced sets around fixed axes on shoe 39 and rotatably abutting section 16. Further, the inner stationary roller guide surfaces 43 of the horizontally V-shaped cross-section boss 44 formed on the outer vertically extending surface 45 of the inner jack section 18. Thus, the inner jack section 18 is mounted vertically reciprocal and telescoped within the intermediate jack section 16. Further, the inner stationray roller guide assembly 22 aids in guiding this inner jack section 18 during vertical reciprocal movement with respect to the intermediate jack section 16.

As in the case of the outer and inner stationary roller guide assemblies 20 and 22, the outer and inner adjustable roller guide assemblies 19 and 21, for all practical purposes, are identical in construction, so that a description of the outer adjustable roller guide assembly 19 will be sufficient to describe both the outer and inner assemblies 19 and 21. As shown in detail, particularly in FIGS. 6, 7 and 8, the outer adjustable roller guide assembly 19 is formed by the shoe 46, the hinge blocks 47 rotatably mounting the rollers 48, the cam blocks 49 andthe adjusting screw 50.

Shoe 46 has the back arcuate and generally vertically extending mounting surface 51, preferably extending substantially the total vertical height thereof and conforming to the previously described inner wall surface 27 of the outer jack housing 14. Further, the front surface 52 of shoe 46 is flat generally vertically extending at the center section thereof, but is formed with the upwardly and downwardly opening cutouts 58, each of which is provided preferably horizontally midway with the vertically extending guide grooves 54, as shown.

Still further, the shoe 46 is provided with the generally vertically extending adjusting screw opening 55 extending vertically therethrough forwardly of the cutouts 53 and horizontally aligned with and opening into the guide grooves 54. Finally, the shoe 46 is formed with the horizontally opposite and generally horizontally extending side mounting bosses 56 which extend angularly forwardly from the shoe front surface 52 at either side thereof and midway of the height of shoe 46, spaced downwardly and upwardly from the cutouts 53, so that in the area of the bosses 56, the shoe front surface 52 is generally V-shaped in horizontal cross section.

Each of the bosses 56 pivotally mounts one of the upper and lower hinge blocks 47 thereon through the pivot pins 57. Further, the hinge blocks 47 are each formed with outwardly and vertically opening generally U-shaped grooves 58, to thereby telescope the bosses 56 and further enclose and rotatably mount the rollers 48 through the roller pins 59.

Hinge blocks 47 extend angled to the side and slightly forwardly similarly to the side mounting bosses 56, and the rollers 48 are rotatably mounted thereon at the upper outer extremities of the upper hinge blocks and the lower outer extremities of the lower hinge blocks, so that the outer cylindrical surfaces 60 of the rollers 48 project angularly outwardly and forwardly from the hinge blocks 47. Thus, the rollers 48 form rotatable surfaces in a forwardly inwardly generally V-shape plane due to the particular angular extension thereof away from the hinge blocks 47 and shoe 46.

The generally V-shaped cam blocks 49 are mounted vertically slidably within the cutouts 53 of shoe 46 and are provided with rearwardly extending guide tracks 61 slidably received within the guide grooves 54 of the cutouts 53, thereby guiding the cam blocks 49 during vertical movement thereof. The upper cam block 49 is formed with side downwardly inwardly angled cam surfaces 62 and the cam surfaces 62 of the lower cam block 49 angle upwardly inwardly.

Furthermore, these side cam surfaces 62 of the cam blocks 49 are angled forwardly inwardly preferably to conform to the angular extension of the side mounting bosses 56, hinge blocks 47 and rollers 48, so that these side cam surfaces preferably extend forwardly in an angled plane substantially parallel to the angled rolling plane of the rollers 48.

Also, angled cam surfaces 63 are formed on each of the hinge blocks 47 normally abutting and conforming to the side cam surfaces 62 of cam blocks 49 so that these cam surfaces 62 and 63 will permit the hinge blocks 47 and, therefore, also the rollers 48, to pivot inwardly toward shoe 46 when the upper cam block 49 is moved upwardly away from shoe 46 and the lower cam block 49 is moved downwardly away from shoe 46. Also, these cam surfaces 62 and 63 will cause the hinge blocks and rollers 48 to pivot away from shoe 46 when the cam blocks 49 are moved in opposite directions, that is, the upper cam block downwardly toward shoe 46 and the lower cam block upwardly toward shoe 46.

The adjusting screw 50 is received vertically slidably through the adjusting screw opening 55 in the shoe 46, with the head 64 thereof rotatably vertically engaged in the countersunk screw opening 65 of the upper cam block 49 and the threaded lower end 66 thereof threadably engaged' in the screw opening 67 of the lower cam block 49.

Thus, when the adjusting screw 50 is rotated clockwise, as shown in FIG. 7, the head 64 will draw the upper cam block 49 downwardly, and the threaded lower end 66 will draw the lower cam block 49 upwardly with reference to the shoe 46 and hinge blocks 47, thereby moving the hinge blocks and rollers 48 individually and simultaneously outwardly, for instance to the position shown in FIG. 8.

Furthermore, the reverse movement of the adjusting screw 50 will permit movement of the hinge blocks 47 and rollers 48 inwardly, due to the reverse movement.v

of the cam blocks 49 with reference thereto and again permitting movement of the rollers individually but simultaneously.

This results in the adjustment of the rollers 48 simply and efficiently, and each roller will move a predetermined amount for the particular threaded movement of the adjusting screw 50. Also, the adjusting screw 50 is free to move vertically during this adjusting operation within the shoe 46 due to the slidable reception thereof through the adjusting screw opening 55.

A lock screw 68 may be threadably received in the screw opening 65 in the upper cam block 49 to abut the head 64 of the adjusting screw 50. Thus, between the adjusting operations of the rollers 48, the lock screw 68 may be inserted tightly abutting the adjusting screw head 64 for retaining the adjusting screw 50 against movement and thereby insure that the cam blocks 49 will remain in their particular adjusted position, retaining the hinge blocks 47 and rollers 48 in the particular adjusted position.

As shown in FIGS. 2 and 3, the outer adjustable roller guide assembly 19 is mounted preferably diametrically opposite from the outer stationary roller guide assembly 20 within the outer jack housing opening 26.

Similar to the outer stationary roller guide assembly 20, the outer adjustable roller guide assembly 19 is mounted with the back mounting surface 51 conforming to and abutting the outer jack housing wall surface 27, with the rollers 48 directed angularly inwardly away from this wall surface and at the upper extremity thereof preferably underlying the cover ring 15. An opening 69 may be formed through cover ring 15 aligned with the adjusting screw 50 of this outer adjustable roller guide assembly 19, thereby providing free access to this adjusting screw and its overlying lock screw 68.

' A particularly formed boss 70 is formed on the outer surface 36 of the intermediate jack section 16, and this boss provides the outwardly angled and vertically extending guide surfaces 71 against which the rollers 48 rotatably abut. Thus, the intermediate jack section 16 is guided during vertical reciprocal movement Within the outer jack housing 14 by the rollers 48 of this outer adjustable roller guide assembly 19, and rollers 48 may be selectively simultaneously adjusted with respect to the guide surfaces 71, as desired and as previously described.

The inner adjustable roller guide assembly 21 is similarly mounted-within the intermediate jack section opening 40 underlying the cover ring 17, with the shoe 46 against the wall surface 41 and with the rollers 48' rotatably abutting guided surfaces 72. formed on the boss 73 of the inner jack section 18. Thus, the inner jack section 18 is guided during its vertically reciprocal movement relative to the intermediate jack section 16 by this inner adjustable roller guide assembly 21, and the same simultaneous adjustment of the rollers 48 of this inner adjustable roller guide assembly 21 may be accomplished as desired.

In the fully lowered position of the jack assembly 12, the upper end surface 74 of the fluid cylinder assembly 23 is spaced below the upper end of the inner jack section 18, with the upper end wall 75 of the inner jack section 18 overlying the cylinder assembly upper end sur face 74 and the vent portion 76 of the cylinder assembly extending upwardly through an opening 77 formed preferably centrally of the inner jack section upper end wall 75, as shown in FIGS. 2 and 3.

Also, the inner jack section 18 is operably connected to the intermediate jaok section 16 by usual equalizing chain assemblies 78, so that every given amount of upward and downward reciprocal movement of the inner jack section 18 within the intermediate jack section 16, will cause a like, but proportionately less, upwardly and downwardly reciprocal movement of the intermediate jack section 16 within the outer jack housing 14.

Thus, for moving the jack assembly 12 from its fully lowered position, as shown in FIG. 3, hydraulic fluid may be pumped by the pump and motor 79 through the fluid inlet 80 and upwardly through the fluid'piston assembly 24 to within the fluid cylinder assembly 23, thereby forcing the cylinder assembly 23 upwardly. At first, the cylinder assembly 23- will move upwardly alone, until the upper end surface 74 thereof engages the upper end wall 75' of the inner jack section 18, and thereafter, the inner jack section 18 will move upwardly with the cylinder assembly carrying with it, as before described, the intermediate jack section 16.

This, therefore, results in vertically reciprocal movement between the inner jack section 18 and the intermediate jack section 16 as well as between the intermedi-. ate jack section 16 and the outer jack housing 14, which reciprocal movements are guided by the inner adjustable and stationary roller guide assemblies 21 and 22 and the outer adjustable and stationary roller guide assemblies 19 and '20.

Furthermorenot only in the original assembly of the jack assembly 17, but also after a period of use causing wear between the various guide rollers and jack sections, adjustments for original tolerances and wear may be made quickly, conveniently and positively by the adjustment, as previously described, of the outer adjustable roller guide assembly 19 and inner roller guide assem bly 21.

One of the more important features of the present-invention is the manner in which the rollers 48- of the outer and inner adjustable roller guide assemblies 19 and 21 may be adjusted with respect to their particular shoes 46 Y 8 and the respective jack sections which are vertically tociprocally being guided thereby.

As previously described, the rollers 48 through their hinge blocks 47 are simultaneously adjusted byzthe movement of a single adjusting screw 50, so that the adjustment thereof is always even and precise, and there is never any problem of misalignment between the jack housing and jack sections or between the various jack sections.

Although in the foregoing, the'adjustable roller guide assembly of the present invention has been described in combination with and usable with vertically reciprocal jack sections, it is obvious that the principles of the present invention can be advantageously used with other forms of reciprocal sections movable in directions other than vertical; It should be understood, therefore, that where the term vertical is used, this could be longitudinal, and where the term horizontal is used, this could be lateral.

In the foregoing description, certain terms have been used for brevity, clearness and understanding, but no unnecessary limitations are to be'implied therefrom, because such words are used for descriptive purposes herein, and are intended to be broadly construed.

Moreover, the embodiment of :the improved construction illustrated and described herein, is by way of example, and the scope of the present invention is not'limited to the exact details of the construction'shown; 1

Having now described the invention, the construction, operation and use of a preferred embodiment thereof, and the advantageous new and useful results obtained thereby; the new and useful construction and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claims.

We claim:

1. Jack construction for chairs andthe like including a stationary jack housing, an intermediate jack section telescoped within the jack housing reciprocalwith respect to the jack housing, an inner jack section mounted telescoped within the intermediate jacklsection reciprocal with respect to said'interrnediate jack section, roller guide means mounted between the jack housing and intermediate jack section and between the intermediate jack section and jack housing for guiding the intermediate and inner jack sections during said reciprocal movement thereof, at least'certain of the roller guide means between the jack housing and intermediate jack section and at least certain of the roller guide means between the intermediate jack section and inner jack section being selectively adjustable, the adjustable roller guidemeans between the jack housing and intermediate jack section having shoe means mounted on one of the housing and section and spaced roller means rotatably abutting the other of the housing and section, the adjustable roller guide means between the intermediate and inner jack sections having shoe means mounted on one of said sections and spaced roller means 'rotatably abutting the other of said sections, mounting means mounting the spaced roller means of each adjustable roller guide means adjustable toward and away from the shoe means thereof, and adjustment means operably connected between the spaced roller means and shoe means of eachadjustable roller guide means for simultaneously moving the spaced roller means toward and away from the shoe means of said each adjustable roller guide means.

2. Jack construction for chairs'and-the like including a housing, a jack section mounted'relatively reciprocal with the housing, roller guide means mounted between the housing and section for guiding certain of the housing and section during said reciprocal movement, at least certain of the roller guide means being selectively adjustable and having shoe means mounted on one of the housing and section andspaced roller means rotatably abutting the other of the housing and'section, a hinge block for each roller means pivotally'connected to the shoe means and rotatably mounting each of the roller means, each hinge block having an angled cam surface formed thereon, cam block means slidably mounted on the shoe means having angled cam surfaces formed thereon simultaneously slidably abutting all of the hinge block angled cam surfaces for simultaneous movement of the hinge blocks toward and away from the shoe means through the slidable abutment of said cam surfaces upon slidable movement of the cam block means on the shoe means, and adjustment means operably connected between the cam block means and shoe means for slidably moving the cam block means with respect to the shoe means.

3. Jack construction for chairs and the like including a housing, a jack section mounted relatively generally vertically reciprocal with the housing, roller guide means mounted between the housing and section for guiding certain of the housing and section during said reciprocal movement, at least certain of the roller guide means being selectively adjustable and having shoe means mounted on one of the housing and section and vertically spaced sets of horizontally spaced rollers rotatably abutting the other of the housing and section, a separate hinge block generally horizontally pivotally connected to the shoe means of the adjustable roller guide means rotatably mounting each of the rollers in each of the sets, the hinge blocks of each set having generally horizontally opposed vertically angled cam surfaces formed thereon, vertically spaced and vertically slidable cam blocks mounted on the shoe means with one of the cam blocks being positioned between the hinge blocks of each set of rollers of the adjust-able roller guide means, the cam blocks having angled cam surfaces formed thereon mating and simultaneously slidably abutting the respective hinge block angled cam surfaces, each cam block of each set of rollers simultaneously moving the hinge blocks of each set of rollers generally horizontally toward and away from the shoe means through the slidable abutment of said cam surfaces and upon generally vertical slidable movement of the cam blocks on the shoe means, and adjustment means operably connected between each of the cam blocks and shoe means of the adjustable roller guide means for simultaneously generally vertically slidably moving the cam blocks with respect to the shoe means for simultaneously moving all of the hinge blocks and rollers generally horizontally toward and away from the shoe means.

i 4. Jack construction for chairs and the like including a stationary jack housing, an intermediate jack section telescoped within the jack housing vertically reciprocal with respect to the jack housing, an inner jack section mounted telescoped within the intermediate jack section vertically reciprocal with respect to said intermediate jack section, roller guide means mounted between the jack housing and intermediate jack section and between the intermediate jack section and jack housing for guiding the intermediate and inner jack sections during said reciprocal movement thereof, at least certain of the roller guide means between the jack housing and intermediate jack section and at least certain of the roller guide means between the intermediate jack sections and inner jack section being selectively adjustable, the adjustable roller guide means between the jack housing and intermediate jack section having shoe means mounted on one of the housing and section and vertically spaced sets of horizontally spaced rollers rotatably abutting the other of the housing and section, the adjustable roller guide means between the intermediate and inner jack sections having shoe means mounted on one of said sections and vertioally spaced sets of horizontally spaced rollers rotatably abutting the other of said sections, a separate hinge block generally horizontally pivotally connected to the shoe means and rotatably mounting each of the rollers in each of the sets of the adjustable roller guide means, the hinge blocks of each set having generally horizontally opposed generally vertically angled cam surfaces formed thereon, generally vertically spaced and generally vertically slidable cam blocks mounted on the shoe means of the adjustable roller guide means with one of the cam blocks being positioned between the hinge blocks of each set of rollers, the cam blocks having angled cam surfaces formed thereon mating and simultaneously slidably abutting the hinge block angled cam surfaces, each cam block of each set'of rollers simultaneously moving the hinge blocks of each set of rollers generally horizontally toward and away from the shoe means through the slidable abutment of the cam surfaces and upon the generally vertical slidable movement of the cam blocks on the shoe means, and adjustment means operably connected between each of the cam blocks and shoe means of each adjustable roller guide means for simultaneously generally vertically slidably moving the cam blocks with respect to the shoe means for simultaneously moving all of the hinge blocks and rollers of said each adjustable roller guide means generally horizontally toward and away from the shoe means thereof.

5. Roller guide construction for mounting between two relatively moving sections for guiding said sections during said relative movement including shoe means mounted on one of the sections and spaced roller means rotatably abutting the other of the sections, a separate hinge block pivotally connected to the shoe means for each of the roller means rotatably mounting each of said roller means, each hinge block having an angled cam surface formed thereon, cam block means slidably mounted on the shoe means having angled cam surfaces formed thereon simultaneously slidably abutting each of the hinge block angled cam surfaces for simultaneous movement of the hinge blocks toward and away from the shoe means through the slidable abutment of said cam surfaces upon slidable movement of the cam block means on the shoe means, and adjustment means operably connected between the cam block means and shoe means for slidably moving the cam block means with respect to the shoe means.

6. Roller guide construction for mounting between two relatively generally longitudinally moving sections for guiding said sections during said relative movement including shoe means mounted on one of the sections and longitudinally spaced sets of laterally spaced rollers rotatably abutting the other of the sections, a separate hinge block generally laterally pivotally connected to the shoe means and rotatably mounting each of the rollers in each of the sets, the hinge blocks of each set having generally laterally opposed longitudinally angled cam surfaces formed thereon, longitudinally spaced and longitudinally slidable oam blocks mounted on the shoe means with one of the cam blocks being positioned between the hinge blocks of each set of rollers, the cam blocks having angled cam surfaces formed thereon mating and simultaneously generally longitudinally slidably abutting the hinge block angled cam surfaces, each cam block of each set of rollers simultaneously moving the hinge block of each set of rollers generally laterally toward and away from the shoe means through the slid-able abutment of said cam surfaces and upon generally longitudinal slidable movement of the cam blocks on the shoe means, and adjustment means operably connected between each of the cam blocks and shoe means for simultaneously generally longitudinally slidably moving the cam blocks with respect to the shoe means for simultaneously moving all of the hinge blocks and rollers generally laterally toward and away from the shoe means. a

7. Roller guide construction for mounting between two relatively generally longitudinally moving sections for guiding said sections during said relative movement including shoe means mounted on one of the sections and longitudinally spaced sets of laterally spaced rollers rotatably abutting -the other of the sections, the shoe means having a front generally longitudinally extending face, a separate hinge block for each roller of each set connected to the shoe means pivotal angularly laterally toward and'away from the shoe means and rotatably mounting each of the rollers in each of the sets, the hinge blocks of each set having generally laterally opposed generally longitudinally angled cam surfaces formed thereon, longitudinally spaced and longitudinally slidable cam blocks mounted on the shoe means with one of the cam blocks being positioned between the hinge blocks of each set of rollers, the cam blocks having angled cam surfaces thereon mating and simultaneously slidably abutting the hinge block angled cam surfaces, each cam block of each set of rollers simultaneously moving the hinge blocks of each set of rollers angularly laterally toward and away from the shoe means through the slidable abutment of said cam surfaces and upon generally longitudinal slidable movement of the cam blocks on the shoe means, an adjustment screw operably connected between each of the cam blocks and the shoe means selectively movable for simultaneous generally longitudinally slidably moving the cam blocks with respect to the shoe means for simultaneously moving all of the hinge blocks and rollers angularly and laterally toward and away from the shoe means, and means for restraining the adjustment screw against movement except during said selected movement 8. lack construction for chairs and the like including a housing, a jack section mounted relatively reciprocal with the housing, roller guide means mounted between the housing and section for guiding certain of the housing and section during said reciprocal movement, at least certain of the roller guide means being selectively adjustable and having shoe means mounted on one of the housing and section and spaced roller means rotatably abutting the other of the housing and section, mounting means individually mounting each spaced roller means on the shoe means individually adjustable toward and away from the shoe means for individual movement away and toward said other of the housing and section, and single adjustment means operably connected between all of the spaced roller means and the shoe means for simultaneously moving all of the spaced roller means at once toward and away from the shoe means.

9. Jack construction for chairs and the like including a housing, a jack section mounted relatively vertically reciprocal with the housing, roller guide means mounted between the'housing and section for guiding certain of the housing and section during said vertical reciprocal movement, at least certain of the roller guide means being selectively adjustable and having shoe means mounted on one of the housing and section and vertically spaced upper and lower roller means rotatably abutting the other of the housing and section, mounting means individually mounting each of the vertically spaced upper and lower roller means on the shoe means individually adjustable generally horizontally toward and away from the shoe means for individual movement generally horizontally away and toward saidother of the housing and section, and single adjustment means operably connected between both of the vertically spaced upper and lower roller means and the shoe means for simultaneously moving both the upper and lower roller means at once generally horizontally toward and away from the shoe means.

10. Jack construction for chairs and the like including a housing, a jack section mounted relatively generally vertically reciprocal with the housing, roller guide means mounted between the housing and section for guiding certain of the housing and section during said vertical'reciprocal movement, at least certain of the roller guide means being selectively adjustable and having shoe means mounted on one of the housing'and section and vertically spaced sets of horizontally spaced roller means rotatably abutting the other of the housing and section, mounting means individually mounting each roller means of each of the vertically spaced sets of roller means on the shoe means individually adjustable generally horizontally toward and away from the shoe means for individual movement generally horizontally away andtoward said other of the housing and section, and single adjustment means operably connected between all 'ofthe roller means of all of the sets of roller means and the shoe means for simultaneously moving all roller means of all sets of roller means at once generally horizontally toward and away from the shoe means. 7

11. Jack construction for chairs and the like including a housing, a jack section mounted relatively reciprocal with the housing, roller guide means mounted between the housing and section for guiding certain of the housing and section during said reciprocal movement, at least certain of the roller guide means being selectively adjustable and having shoe means mounted on one of the housing and section and spaced roller means rotatably abutting the other of the housing and section, mounting means individually mounting each of the spaced roller means on the shoe means individually adjustable toward and away from the shoe means for individual movement away and toward said other of the housing and section, each of the roller means having cam surface means formed thereon, cam block means slidably mounted on the shoe means having cam surface means simultaneously abutting each of the roller means cam surface means for simultaneously moving the roller means toward and away from the shoe means through slidable movement between said cam block means and roller means cam surface means and single adjustment means operably con nected between the cam block means and the shoe means for slidably moving the cam block means on the shoe means to simultaneously move all the roller means upon movement of said single adjustment means.

12. Roller guide construction for mounting between two relatively moving sections for guiding said sections during said relative movement including shoe means mounted on one of the sections and spaced roller means rotatably abutting the other of the sections, mounting means individually mounting each of the spaced roller means on the shoe means individually adjustable toward and away from the shoe means for individual movement away and toward said other of the sections, and'single adjustment means operably connected between all of the spaced roller means and the shoe means for simultaneously moving all of the spaced roller means at once toward and away from the shoe means.

l3. Roller guide construction for mounting between two relatively moving sections for guiding said sections during said relative movement including shoe means mounted on one of the sections and longitudinally spaced sets of laterally spaced roller means rotatably abutting the other of the sections, mounting means individually mounting each of the roller means of each of the longitudinally spaced sets of roller means on the shoe means individually adjustable toward and away from theshoe means for individual movement away and toward said other of the sections, and single adjustment means operably connected between all of the roller means of all of the sets of roller means and the shoe means for simultaneously moving all roller means of all sets of roller means at once toward and away from the shoe means.

14. Roller guide construction for mounting between two relatively moving sections for guiding said sections during said relative movement including shoe means mounted on one of the sections and spaced roller means rotatably abutting the other of the sections, mounting means individually mounting each of the spaced roller means on the shoe means individually adjustable toward and away from the shoe means for individual movement away and toward said other of the sections, each of the roller means having cam surface means formed thereon, cam block means slidably mounted. on the shoe means having cam surface means simultaneously abutting each of the roller means cam surface means for simultaneously moving all of the roller means toward and away from taneously move all the roller means upon movement 01 said single adjustment means.

References Cited in the file of this patent UNITED STATES PATENTS Bronzan et a1. Nov. 7, 1939 

